emulator??

Hello
lots of people talk about emulator
what is it?
is it the thing that lets you play games on your PC?
how does it work??

http://en.wikipedia.org/wiki/Emulator
Basically, an emulator imitates a machine, on another machine.
For example, ePSXe emulates a playstation on a pc.
In other words, with this specific emulator, you can play playstation games on your computer.
However, there are emulators that work on certain consoles, cellular phones, etc.
It all depends on what you are looking for.
Search the forums, there is a lot of info on emulators around here.
Also, google is your friend.

Thank youI been wanting to try it
but I'm not really sure what it is exactly